BT and Openreach workers are to stage fresh strikes in a long-running dispute over pay.
The Communication Workers Union (CWU) said its members will walk out on October 6, 10, 20 and 24.
The action will include the tens of thousands of Openreach engineers and BT call centre workers who have walked out in previous months.
The dispute centres on workers opposing the imposition by company management of an “incredibly low” flat-rate pay rise of £1,500 which the union said was a real-terms pay cut because of the soaring rate of inflation.
The union said 999 emergency call handlers will also be on strike next month.
CWU general secretary Dave Ward said: “This dispute is modern Britain in a nutshell: lives are at risk because a company’s top brass won’t listen to workers.
“This decision was not taken lightly, but our union’s repeated attempts to initiate discussions was declined by a management who clearly believe they are above negotiating a fair deal for people who make massive profits for them.
“999 operators are using foodbanks, they’re worried about the bills and are being stretched to the limit.
“It’s no surprise that the goodwill of workers has run dry, and that services will now be hampered.
“BT management clearly has no appreciation of their workers’ value – but this union does, and we will keep on fighting this company’s attempt to plunge its workers into even further hardship.”
CWU deputy general secretary Andy Kerr said: “It is downright disgraceful that BT Group’s refusal to treat its members with an ounce of dignity has come to this.
“Time and time again, we have asked for negotiations to resolve what may well be a dangerous dispute for many, only to be ignored by a senior management that could not be less interested in addressing the anger that exists in their workplaces.”